A conversation is a forum in which participants attempt to transfer information in real time to one another via means such as voice, keyboards and wireless devices. Currently, communications networks are structured with the assumption that such transferred data are to be immediately consumed by the receiver(s). The data disappear after being delivered. Examples of conversations utilizing such communications networks include telephone calls, conference calls, electronic drawing boards and instant messaging.
Under field conditions, data transmission can be briefly interrupted or lost. In such cases, instant replay can be helpful to resynchronize the conversation. For example, during a conversation conducted via a telephone network, voice data can be corrupted by jitters on the network circuit or the data may be received but not properly processed because the listener was distracted by some external events (e.g., baby crying). In a wireless telephone communication, the data may have passed through most of the network intact, only to be corrupted by weather conditions between the wireless base station and the handset. Non-voice data may similarly be corrupted during transmission.
It is known to replay one-way streaming data such as TV transmission. For example, the digital video recording devices used in conjunction with TiVo, Inc.'s on-line service is capable of buffering viewed content for immediate replay. Similarly, many personal computer-based media players allow replay of streaming media such as video webcasts through the use of a buffering system. In each of those cases, the replay buffer is constructed at the receiving node of the network, using data received at that node. While useful in cases where the data is delivered intact to the receiving node, such devices are not useful if the data is corrupted upstream of the receiving node. Furthermore, the receiving party must purchase, install and activate a software and/or hardware device capable of buffering and replaying the signal.
The scroll-back feature of a terminal device, used in conjunction with instant messaging, provides some basic replay capability in the case of a conversation involving multiple parties. As with the buffering capability described above, that capability is not effective in replaying communications that have been corrupted upstream of the receiving node.
U.S. Pat. No. 5,477,487 describes a device that is used in conjunction with a receiver such as a car radio. The device has access to an audio signal produced by the receiver, and stores the audio signal in the form of a digital buffer that may be replayed by pressing a button. The buffer enables a listener, such as a distracted car driver, to replay a missed portion of the one-way broadcast. Again, the device is not useful if the broadcast was missed because it did not reach the receiver.
Users of cell phones, personal digital assistants (PDA's) and other mobile devices often encounter reception problems that arise in the final, wireless portion of the connection. A buffering system within the mobile device itself would not be helpful if a communication became garbled before reaching the mobile device. Because portability and compactness are important in such a device, it is furthermore undesirable to add to the device the components and circuitry necessary to implement a data buffering system.
It is therefore desirable to provide a method and apparatus for buffering information for replay on demand by the receiving party, wherein the replayed material is not affected by previous transmission errors upstream of the receiver, and no additional devices are necessary at the receiving node.